Doubletop and falcate braces

[Davelang]

Just wondering if anyone has guidelines for using falcate bracing on a classical with nomex honeycomb doubletop. This top is very stiff in long grain direction, in fact much much stiffer than a comparable solid top. Im sure I could make a braceless top with it.

I am wondering if I should just start with 9mm falcate braces and thin to frequency performance vs start with low profile falcate. I am wondering if a falcate brace can be used for modal control and less so for strength of construction

[kiwigeo]

I am wondering if I should just start with 9mm falcate braces and thin to frequency performance vs start with low profile falcate. I am wondering if a falcate brace can be used for modal control and less so for strength of construction

If you do your falcate braces ala Gore and Gilet with CF tow underneath and on top of the brace then you don't have the option of trimming the brace once its stuck to the top.

[Davelang]

I was thinking of not using the CF tow and just using some diminuitive falcate braces as tone, mode control only. I certainly can do some deflection tests, bridge tilt tests to be sure I'm not under built. I'm just not sure how much of the falcate braces are for construction and how much is for managing modal nodes and antinodes. Might be best just to try it out and see what happens.

[Trevor Gore]

In general, on a closed box, bracing alters mode frequencies rather than mode shapes, which are generally symmetric. To alter mode shapes, braces have to be added that are so stiff that the usual outcome (with a few notable exceptions) is that the top has a much lower monopole mobility than it otherwise would have and is therefore not very responsive. The guys at the Australian Guitar Making School have explored double tops quite extensively but, as I understand it, have usually used a light permutation of Simon Marty bracing. They tell me it's easy to end up too stiff. Aiming for ~2 degrees bridge rotation should get you in the ball-park.

[Davelang]

Thanks all. I'm going to press on with the doubletop falcate. Uncharted territory make it fun. I'll post what I do and how it turns out ?. Greatings from South Dakota!

[kiwigeo]

Thanks all. I'm going to press on with the doubletop falcate. Uncharted territory make it fun. I'll post what I do and how it turns out ?. Greatings from South Dakota!

Welcome to the forum Dave and yes please post up some progress pics of your build.